Fish Oil for Dogs: Dosage, Benefits, and Side Effects

Fish oil is one of the most popular supplements for dogs, but many dog parents wonder whether it’s truly necessary. Do dogs need fish oil? The answer depends on your dog’s diet, health needs, and lifestyle. Fish oil provides essential omega-3 fatty acids that support heart health, reduce inflammation, promote a shiny coat, and even improve cognitive function in aging dogs. However, it’s important to understand how to choose high-quality fish oil, the proper dosage, and any potential risks.

This guide covers everything you need to know about fish oil for dogs, including its benefits, side effects, how to store it, and natural food sources that contain omega-3s.

What Is Fish Oil and Why Is It Important for Dogs?

Fish oil is derived from fatty fish like salmon, sardines, and anchovies. It contains two essential omega-3 fatty acids: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These fatty acids play a vital role in reducing inflammation, supporting heart health, and improving brain function. Since dogs cannot produce enough omega-3s on their own, they must obtain them from their diet or supplements.

Some dog parents confuse fish oil with cod liver oil, but they are not the same. Cod liver oil comes from the liver of codfish and contains high levels of vitamins A and D, which can be harmful in excess. Regular fish oil is a safer and more effective choice for providing essential omega-3s.

Health Benefits of Fish Oil for Dogs

Fish Oil Protects the Heart

Omega-3s in fish oil help maintain cardiovascular health by reducing triglyceride levels, lowering blood pressure, and improving circulation. Dogs with heart conditions may benefit from fish oil as part of their overall treatment plan.

Fish Oil Relieves Dry, Flaky Skin

If your dog suffers from dry skin, excessive shedding, or allergies, fish oil can help by reducing inflammation and promoting healthy skin. Many veterinarians recommend fish oil to improve coat health and reduce itchiness caused by environmental allergies.

Fish Oil Aids Arthritic Joints

Senior dogs or those suffering from arthritis may experience joint pain and stiffness. The EPA in fish oil has natural anti-inflammatory properties that help reduce swelling and improve mobility.

Fish Oil Slows the Progression of Kidney Disease

Dogs with kidney disease may benefit from fish oil due to its ability to lower protein loss in urine and reduce inflammation in the kidneys. Many veterinarians recommend omega-3s as part of a kidney-friendly diet.

Fish Oil Improves Neurologic Development and Cognitive Function

For puppies, DHA is essential for brain development and learning. In senior dogs, fish oil may help slow cognitive decline, improve memory, and support overall brain function.

Does Fish Oil Help with Dog Anxiety?

Some studies suggest that omega-3s may support brain health in anxious dogs. While fish oil is not a cure for anxiety, it can be a helpful supplement when combined with behavioral training and a balanced diet.

How Fish Oil Helps With Canine Allergies and Inflammation

Dogs suffering from allergies or chronic inflammation often benefit from fish oil. Omega-3s help reduce itchiness, hot spots, and redness caused by allergic reactions. They also support the immune system, helping dogs better tolerate allergens in their environment.

For dogs with chronic inflammatory conditions like dermatitis or inflammatory bowel disease, fish oil can provide relief by reducing swelling and irritation.

How to Choose a Good Fish Oil for Your Dog

Not all fish oil supplements are created equal. When selecting fish oil for your dog, consider the following:

• Purity: Choose a fish oil that has been purified to remove heavy metals and contaminants.
• Third-Party Testing: Look for brands that provide testing results to ensure quality.
• Source: Wild-caught fish like anchovies, sardines, and mackerel are preferable to farmed fish.
• Form: Fish oil is available in liquid, capsules, and chewable treats. Choose the option that is easiest for your dog to consume.

Best Dosage of Fish Oil for Dogs

The recommended dosage varies based on your dog’s weight and health condition. Most veterinarians suggest 20 to 55 mg of EPA and DHA per pound of body weight per day. Always consult with your veterinarian before starting a new supplement.

Does Dog Food Typically Contain Fish Oil or Omega-3s?

Many commercial dog foods contain some level of omega-3s, but the amounts may not be sufficient to provide all the benefits of fish oil. Checking the ingredient list and guaranteed analysis can help determine whether additional supplementation is needed.

Can You Give a Dog Human Fish Oil?

While human fish oil is similar to pet-specific versions, some human supplements contain added ingredients like artificial flavoring or preservatives that may not be safe for dogs. It’s best to use fish oil formulated specifically for pets.

Are There Dog-Safe Foods That Naturally Contain Fish Oil?

If you prefer to provide omega-3s through food rather than supplements, consider incorporating the following dog-safe foods:

• Salmon
• Sardines (packed in water, no salt added)
• Herring
• Anchovies
• Mackerel

These fish are excellent natural sources of omega-3s, but they should be fed in moderation to avoid excessive fat intake.

Signs Your Dog Might Be Deficient in EPA or DHA

• Dry, flaky skin and excessive shedding
• Joint pain or stiffness
• Cognitive decline in older dogs
• Poor wound healing
• Increased inflammation or allergies

If you notice these signs, talk to your veterinarian about whether adding fish oil to your dog’s diet could help.

How to Care for and Store Fish Oil

To prevent oxidation and spoilage, store fish oil properly:

• Keep it in a cool, dark place.
• Refrigerate liquid fish oil after opening.
• Check expiration dates and discard rancid-smelling oil.

Proper storage ensures that your dog receives the full benefits of fish oil without the risk of harmful oxidation.

Are There Risks or Side Effects of Fish Oil for Dogs?

While fish oil offers numerous health benefits, it’s important to be aware of potential risks.

Digestive issues. Some dogs may experience diarrhea, vomiting, or an upset stomach if given too much fish oil. Introducing it gradually into their diet can help prevent these issues.

Increased bleeding risk. Fish oil has natural blood-thinning properties. Dogs undergoing surgery or those with clotting disorders should use fish oil supplements cautiously.

Oxidation concerns. Fish oil can become rancid over time, losing its potency and producing harmful free radicals. Storing fish oil properly in a cool, dark place and checking expiration dates can prevent these risks.

Alternative Plant-Based Sources of Omega-3s

If you are looking for alternatives to fish oil, there are several plant-based sources of Omega-3s that can provide similar benefits.

Algal oil. This is one of the best plant-based sources of DHA and EPA, derived from marine algae. Since fish get their Omega-3s from algae, algal oil provides a direct and sustainable alternative for dogs.

Flaxseed and chia seeds. These seeds are rich in ALA (alpha-linolenic acid), a type of Omega-3 that the body converts into EPA and DHA. While the conversion rate is lower in dogs compared to direct fish oil or algal oil, they still provide beneficial fatty acids.

Hemp seeds. Hemp seeds contain a balanced ratio of Omega-3 and Omega-6 fatty acids, supporting skin, coat, and joint health. They are a great option for pet owners looking for plant-based nutrition.

Comparing fish oil with plant-based sources, the main difference is bioavailability. While fish oil and algal oil provide direct DHA and EPA, flaxseed, chia seeds, and hemp seeds require the body to convert ALA into these essential fatty acids. This means dogs may need a higher quantity of plant-based sources to achieve the same benefits as fish oil.

Final Thoughts

Do dogs need fish oil? While not every dog requires supplementation, many can benefit from the anti-inflammatory and heart-protective properties of omega-3s. Whether you choose to add fish oil to your dog’s diet or offer omega-3-rich foods, ensuring your dog gets these essential fatty acids can improve their overall health.

What has been your experience with fish oil or omega-3 supplements for your dog? Have you tried any plant-based alternatives? Let us know in the comments!